hello everybody my name is Iman welcome back to my YouTube channel today we're starting an MCAT organic chemistry playlist this playlist will follow the same format as my other MCAT playlist so what we're gonna do is for each chapter I'll have lecture Style videos to review all the material and then those videos will be followed by practice problems that relate to all the topics we cover for said chapter we're starting today with our first chapter which is all about nomenclature nomenclature is one of the most important prereqs for answering organic chemistry questions on the MCAT if you don't know which chemical compound the question is asking about it's going to be very hard to get the answer right which is why it's important for us to cover nomenclature as the very first thing all right in this chapter we're going to cover a couple of objectives first objective is we're going to learn the IUPAC naming conventions we're gonna go over the steps that you have to take in order to name a compound then in the next three objectives we're going to focus on the presence of different functional groups in our compounds and how that alters our naming so we're going to cover in our second objective hydrocarbons and alcohols and how we go about naming those all right and our third objective we're going to cover aldehydes and ketones and how we go about naming molecules and compounds that have aldehydes and ketones and then our fourth objective is focused on carboxylic acids and their derivatives which are going to be Esters amide and anhydrides and how we go about naming molecules and compounds with these functional groups and then last but not least we'll talk about all these functional groups and how we go about naming them if there's more than one what is the priority of these functional groups in regards to nomenclature all right here I have a quick reminder of the functional groups alkanes alkenes we have um ketones and aldehydes years ethers amines alcohols carboxylic acids Esters amides all of the functional groups you need to know for the MCAT here and of course we're gonna we're going to focus on each one as we cover it in this chapter as well so I'll remind you what an alkane is I'll remind you what an alcohol is and so on and so forth but just for reference as you're using these notes to study I have them here for your convenience fantastic with that we're going to start with our first objective IU pack naming conventions all right now let's begin by examining IUPAC naming conventions before we highlight specific compounds and functional groups the primary goal of the IUPAC naming system is to create an unambiguous relationship between the name and structure of a compound so in chemistry every single molecule needs a unique name we can't have two molecules with the same name that would create havoc and chaos and we do not want that and so we have this naming convention to make sure that every compound and molecule has a unique name now there are four parts to naming the first part is the root or parent chain this tells us about the overall chain length so here you'll identify the longest carbon chain and if there is a tie between two chains of of equal length all right we're gonna choose the chain with the greatest number of substituents all right for Rings we're going to use things uh prefixes like cyclo with the chain name the second thing that is part of naming convention is modifiers this will tell us about what functional groups are attached to the chain we're going to worry about how this modifies the naming system when we cover objectives two three and four all right then the third part is the substituents this is what is branching off the chain and we're going to add the suffix Y and the suffix y l to them when we are naming it now of course we're going to go in more details don't worry for numbering your chain you're going to start with the closest substituent all right because you want you want the the substituents to have the lowest number that first substituent especially to have the lowest number possible for numbering your chain you're gonna you're gonna start from the closest substituent but if there is a tie you're going to compare the locations of the next substituent and the next and you want to make sure that the first substituents get those lowest numbers all right and then taking all these parts you can construct the molecule's name keeping in mind a couple of important parts always name your substituents in alphabetical orders you're going to use commas to separate numbers from numbers and dashes to separate numbers from letters and sometimes you will have complex substituents where you have to go through all the naming rules for in addition to all right but worry not we're going to cover all those in this lecture we're also going to do plenty of practice problems in that resp in that video after the lectures all right so then the question begins right well Iman what are the DAR naming steps you've given us the components but what are the exact steps and to you I say the steps are the following one you want to identify the longest carbon chain containing the highest order functional groups the second step is to number the chain the third step is to name the substituents the fourth step is to assign a number to each substituent and the fifth step is to complete the name let's go through each of these steps in a lot of details that first step is to identify the longest carbon chain containing the highest order functional group all right what is happening here this is this is what will be called the parent chain it is going to be used to determine the root of the knee all right keep in mind that if there are double or triple bonds between the carbon they must be considered when identifying the highest order functional groups all right we'll examine priorities of functional groups throughout this chapter all right but keep in mind that the highest priority functional group all right that's going to be the group with the most oxidized carbons is going to provide the suffix this may sound this step may sound easy but you have to be very careful all right the molecule may be drawn in a way that the longest chain is not immediately obvious to us all right and if there are two or more chains of equal length then the more substituted chain is going to get priority as the parent chain now let's say that you identify that the longest carbon chain for example has six carbons one two three four five six then what that means is since the longest parent chain is going to be used to determine the root of the name and it has six then hexane will be the name of that alkane all right that's going to be the root of the name if there are other substituents we will list out those substituents and end everything off with hexane because the parent chain the longest carbon chain the longest um I should say the longest carbon chain containing the highest order functional groups is six carbons all right and so we write out the rest of the name ended off with hexane and when there are other functional groups for example if there is a carboxylic acid all right then hexane gets changed to something else because now our longest carbon chain with the highest order functional group is not just carbon attached to carbon attached to carbon but now there is a carboxylic acid and that will modify these names all right and that is what we're covering objectives two three and four all right so that's our first rule identify the longest carbon chain containing the highest order functional group the second step is to number the chain in order to appropriately name a compound we need to number the carbon chain as a convention the carbon number the carbon numbered one will be the one closest to the highest priority functional group so just looking at this molecule that we've drawn a carboxylic acid for this carbon that's part of the carboxylic acid will be numbered one right because it is the one that's closest to the highest ordered the highest priority functional group now if the functional groups all have the same priority numbering the chain should make the number of the substituent the substituent carbons as low as possible now after we've discussed the functional groups um that are most commonly tested on in objectives two three and four we're going to review a table of those functional groups in order of priority for now keep in mind that the most oxidized that the more oxidized the carbon is the higher priority it has in the molecule oxidation state increases with more bonds to hetero atoms so those are atoms besides carbon and high hydrogen so atoms like oxygen nitrogen phosphorus or halogens and it decreases with more bonds to hydrogen all right let me repeat that oxidation state increases with more bonds to heteroatoms and decreases with more bonds to hydrogens now just like straight chains rings are numbered starting at the point of greatest substitution continuing in the direction that gives the lowest numbers to the highest priority functional groups all right somewhat counterintuitive if there is a tie between assigning priority in a molecule with a double and triple bonds actually the double bond takes precedence all right so that is numbering the chain so we've covered the first rule identify the longest carbon chain containing the highest priority we learn to number the chain number the chain in in the way that the highest priority functional groups receives the lowest possible numbers and so do the substituents and now we move on to step number three name the substituents substituents are functional groups that are not part of the parent chain a substituent's name will be placed at the beginning of the compound name as a prefix and it'll be followed by the name of the longest chain all right remember that only the highest priority functional groups will determine the suffix for the compound and must be part of the parent chain carbon chain substituents though they're named like alkanes but we were we were replaced with the suffix yl instead of a n e all right we also see here some examples um of that so if you remember this graph right here tells you if you have a two carbon chain then your root name is ethane three carbon chain propane five carbon chain you know pentane six carbon chain hexane now if we have this six carbon chain 6 and we have a substituent here and a substituent here all right so here's our parent chain for example all right we have this substituent right here that's a two carbon chain so what do we call the substituent that has two carbons we don't call it ethane no because it's a substituent we replace the A and E with a Y so that substituent is called ethyl not ethane because it is a substituent this is another substituent has one carbon we don't call it methane because it's a substituent we call it methyl we replace the A and E with y l so this is for substituents that are hydrocarbons of course we can't remember we don't want to forget about modifiers we'll get to that later now we also here see examples all right of What alternative alkyl substituents might look like all right and they have special names as well so you can have a substituent that looks like this all right all right we have these like three methyl groups coming off of this carbon this could be a substituent in our long carbon chain what do we call the substituent it has a special name called um t-butyl all right this is another special case this is called neopental all right you notice it has a carbon that has three methyl groups and one ch2 group what does this look like in a long carbon chain as a substituent it looks like this all right that's neopental then we have isopropyl isopropyl looks like this all right so this is t-butyl tert-butyl all right this is isopropyl all right this is neopental all right what else do we have we have sec butyl all right and we have isobutyl so let's see what a sec butyl would look like it would look like this this and then this and then there's this group right here all right so this is second butyl and this is isobutyl this would look like something like this all right so these are common alternative alkyl substituent names and these are ones that are very very recommended for you to remember for the MCAT so I would definitely recommend you commit these two memories all right now if there are multiple substituents of the same type all right Pretend This carbon chain has two isopro isopropyl substituents then you would begin to use um prefixes like die try and tetrip that we that would be added before the the substituent name so if you have two isopropyl groups in your naming system you would write dye isopropyl to denote it and then of course you'd write the numbers that they are located on on that carbon chain all right so you can use prefixes like die try if you have multiple of the same substituent in your naming all right now the fourth thing uh is the fourth rule is assign a number to each substituent so you want to pair the substituents that you have named to the corresponding numbers in the parent chain and again this is so important multiple substituents at the same time will will get both uh we'll get the die try Tetra prefixes that we've previously stated as well as their carbon number designation all right even if they're on the same number all right so if you have two isopropyl groups on the same number on the same carbon atom you'll write oh okay um four four diisopropyl it as part of your knee and then last but not least five step five is complete the name names always begin with the name of the substituents in alphabetical order with each substituent preceded by its number all right note however the prefixes die try and Tetra as well as the hyphenated prefixes like n and tert are ignored when you're alphabetizing all right non-hyphenated roots that are part of the name however are included so these are modifiers like ISO Neo or cyclo those are you consider those when you are alphabetizing then the numbers are separated from each other with commas and from words with hyphens and we finally finished the the name with the name of the backbone chain including the suffix for the functional group of the highest priority so let's do some quick practice problems here we have this compound and we want to name it all right so the first step is to identify the longest carbon chain all right with the highest priorities what you notice here is that these are all just alkenes these are just carbons bonded to carbons and hydrogens and that's it all right so our longest carbon chain is this one all right and it's just carbons it's just carbons bonded to carbons and hydrogens so this is alkanes all right and it has one two three four five six seven eight carbons so our root name is going to be octane because this is just an alkane chain all right there are no modifiers there's no aldehydes ketones carboxylic acids that would modify this octane root name all right we're gonna we haven't covered those anyway so I'm not going to do any example problems of them just yet so there are no modifiers then we want to look for substituents we've identified our root chain and we've noticed that there are two substituents we have this ethyl group right here and this methyl group right here two carbons are called ethyl that's this group right here this is just one carbon atom this is called a methyl all right now we want to number this we want to appropriately number the locations here so we can go this way one two three four five six seven eight or we can number the other way all right how do we figure out how we want to number well we want lowest numbers for the substituents all right for that first substituent we want the lowest number for this way we'll get our lowest substituent at four for this way we get our low substituent as before that's a tie all right if you you number them in either direction you get a substituent at four in this case of a tile all right in the case of a tie like this the lowest number should be assigned alphabetically so this 4 is associated with an ethyl group this four is associated with a methyl alphabetically e comes before M so we're going to adopt this naming location all right so this is the numbering the appropriate numbering of our parent chain so this is what we're following here all right so now looking at this we've assigned that there is a methyl there's a ethyl at four so four ethyl and there is a methyl at five so we have a five methyl now as a last step we can make the name all right we name it in order starting with substituent first so for FL e comes first so we put the substituent for ethyl first followed by 5-methyl all right 5-methyl all right remember that um uh we not we we use um commas for multiple numbers numbers are separated from each other with commas and numbers are separated with words from hyphens which is why we have hyphens between foreign ethyl and a hyphen between ethyl and five and why we have a hyphen between five and methyl all right so those are the two substituents now that we've written both substituents in alphabetical order we end the name with the root which is Octane and so the name of this molecule is four ethyl 5-methyl octane all right here's another example I want you to attempt naming this compound and let me know what you get for it down below all right so make an attempt to name this molecule and let me know what you get all right with that though we can start moving into further objectives I'm actually going to stop the video here in the next video we'll continue objectives two through five let me know if you have any questions comments concerns down below other than that good luck happy studying and have a beautiful beautiful day future doctors